deb http://apt.wicd.net gutsy extrasAdd the signing key with:
Reload apt or Synaptic and install Wicd. Under Applications>Internet choose Wicd. Locate your wireless connection and enter your encryption details. Under preferences choose "wext" as the WPA supplicant Driver. Hit connect.
wget -q http://apt.wicd.net/wicd.gpg -O- | sudo apt-key add -
To get the tray icon loading automatically on boot go to System>Preferences>Sessions and in the Startup tab add a new entry called "Wicd", with "/opt/wicd/tray.py" as the start command. Save and reboot.
If all goes wrong, to reinstall the default Network Manager, simply reinstall network-manager and network-manager-gnome (which automatically uninstalls Wicd in the process). You may need to connect via Ethernet to receive these updates....however, in some cases, there may already be a copy in the /var/cache/apt/archives.